1. Field of the Invention
The present invention relates generally to a hand tool, and more particularly to a bleeder fitting structure.
2. Description of the Related Art
FIG. 1 shows a conventional bleeder 1, which is generally used as a connection member of a closed hydraulic circuit such as a hydraulic brake system for connecting with outer side. The bleeder 1 enables a user to conveniently replace the fluid in the circuit. In use, it is necessary to rotate the bleeder 1 so as to communicate the inlet passage 1a of the bleeder 1 with the hydraulic circuit or discommunicate the inlet passage 1a from the hydraulic circuit. Also, it is necessary to connect a proper connection pipeline with the tapered connection end 1b of the bleeder 1 so that the connection pipeline can connect with the hydraulic circuit via the bleeder 1.
In order to facilitate the above operation, a conventional fitting tool 2 has been disclosed as shown in FIGS. 2 and 3. With the fitting tool 2, a user can apply a rotating force to the bleeder 1 and connect the fitting tool 2 with the connection end 1b at the same time. Please further refer to FIG. 1. The fitting tool 2 has a metal-made hollow socket 2a for fitting on a nut 1c positioned on inner side of the connection end 1b of the bleeder 1 so as to apply a rotational force to the bleeder 1 to rotate the bleeder 1. A flexible elastic sleeve 2b is coaxially inlaid in the hollow socket 2a to form a radially expandable and restorable elastic connection opening for tightly fitting on the connection end 1b as a passage in communication with the external connection pipeline.
Such fitting tool 2 enables a user to easily operate the bleeder 1. However, there are various conventional bleeders with different structures or sizes are employed in different hydraulic circuits in accordance with the requirements thereof. Only when the fitting tool 2 can be fitted on the nut of a bleeder and tightly connected with the connection end of the bleeder, the fitting tool 2 can be applied to the bleeder to replace the fluid in the hydraulic circuit. However, in the existent industrial product standards, there is not yet any suitable standard to follow. Therefore, there are various bleeders with different sizes or configurations of connection ends exist in this field at the same. In this case, due to the limitation of its own structure, the fitting tool 2 can be only applied to the connection ends of the bleeders with a smaller range of size to rotate and connect with the connection ends.
Substantially, the flexible elastic sleeve 2b of the fitting tool 2 serves as a fitting structure for connecting with the connection end 1b of the bleeder. However, the fitting tool 2 is such limited that the flexible elastic sleeve 2b can be only deformed to an extent within a small range due to its own material properties. With respect to the connection ends of the conventional bleeders with different sizes or configurations, the fitting tool 2 cannot be applied to different bleeders with different connection ends the size or configuration of which widely ranges. As a result, the application range of the fitting tool 2 is limited and a user cannot conveniently use the fitting tool 2.